1. Field of the Invention
The present invention generally relates to a telecommunications network. More particularly, one aspect of the present invention relates to a method and apparatus of automatically detecting fraudulent calls in a telecommunications network and another relates to a method of controlling calls over a telecommunications network.
2. Background of Related Art
Fraudulent use of a telephone communications network can cost the telecommunications operator a significant amount of money. Rule based fraud detection systems have been developed with a view to combating fraud in a telecommunications network. In such systems if a particular usage of the network, determined from a call record, triggers one or more of the predefined rules, an alarm is generated enabling human operators to take the necessary action. While such systems have had some success in combating fraud, difficulties seem to arise due to the sheer number of alarms that can be generated within a short time. Typically, fraud detection operators may have tens of thousands of live alarms to deal with during a day and it is therefore generally impractical to deal with each individual alarm as it arises. Methods have been developed for consolidating or grouping the fraud alarms based on their priority and for identifying patterns in the alarms once generated. Such rule based fraud detection systems however only operate once alarms have been raised.
In accordance with one aspect the present invention provides method of automatically detecting fraudulent calls in a telecommunications network, the method comprising the steps of:
determining the origination of the calls; and
determining whether the call is likely to be a fraudulent call using a predetermined pattern of previous or expected calls specific to the origination.
In accordance with a second aspect the present invention provides apparatus for automatically detecting fraudulent calls in a telecommunications network, the apparatus comprising:
determining means for determining the origination of the call;
storage means for storing data for a pattern of previous or expected calls specific to originations; and
fraud detecting means for determining whether the call is likely to be a fraudulent call using the determined origination of the call and the stored pattern of calls specific to the origination.
Thus in accordance with the present invention the pattern of use of the telecommunications network is used which is specific to the origination of the call. Fraudulent activity can be determined by detecting a deviation in the call from the predetermined pattern for the origination of the call. The predetermined pattern comprises information on calls over a period of time and the time of the current call can be used to determine whether the call fits the pattern.
Preferably the origination is determined by receiving a call record containing information on the call. Typically in a telecommunications network when a call is initiated a call record is sent to the exchange which contains information for example identifying the origination, the destination, the time of initiation of the call and the date. By determining the origination of the call from the call record at the initiation of the call, the determination of whether the call is likely to be a fraudulent call can be determined as the call is made. This allows the call to be disallowed or disconnected if the call is determined to a call which lies significantly outside the predetermined pattern of calls.
In order to accommodate changes in the calling behaviour of the originator, the predetermined pattern of calls can be adaptively modified. Such a modification can give a greater weighting to more recently made calls. All the calls which do not deviate significantly from the predetermined pattern of calls can be used to update the pattern. Also, calls which have been determined to be fraudulent can be used to adaptively modify the predetermined pattern of calls once they have been investigated and cleared by, for example, an operator. In this way the pattern of calls can be adapted to more accurately reflect the expected call behaviour of an origination.
The term xe2x80x98originationxe2x80x99 is used in the specification to refer to any identifiable point of origin of a call in a telecommunications network. For example, an origination can comprise an individual user or group user identification code. Examples of such an identification code are a personal number which can be input using a telephone key pad. Such a system is used for instance when using a charge-card. Also for a mobile telephone the SIM card can be used to provide a unique identification code. A code can be assigned to an individual user or a group of users and is independent of the node in the telecommunications network i.e. the telephone number from which the call is made. Alternatively or in addition the identity of a node or group of nodes in the telecommunications network can comprise the origination i.e. a telephone number from a group of telephone numbers, or an area code. Further, the origination can comprise the geographical location from which the call is made. For calls made from mobile telephones, the geographical location can comprise a true geographical location which can, for example, be obtained from the base stations in the cellular network. For a call originating from a conventional telephone handset, the geographical location can be obtained from the telephone number and can be provided as an exact address, or an area such as a town or country.
Thus, one or a combination of these pieces of information identifying the origination of the call can be used to choose a predetermined pattern to be used for the call. For example, for a charge-card user, there may be more than one predetermined pattern termed a user profile assigned to that charge-card depending upon the telecommunications node used to make the call or the geographical location from which the call was made. The user""s calling behaviour may be different for different telecommunications nodes and/or different geographical locations. The same is true for mobile telephone users. The pattern of calls in different geographical locations can be quite different and therefore different user profiles can be provided.
In one embodiment the user profile includes information on the call destination for the pattern of calls and thus for the call made the destination is determined in order to determine whether the call fits the normal pattern of calling behaviour for the origination. The call destination information can comprise information identifying a node or group of nodes in the telecommunications network i.e. a specific telephone number, group of numbers, or an area code, and/or a geographical location.
In an embodiment of the present invention the time and/or day or date of the call is determined and the user profile includes information on the time of day of the calls, the day or date of the calls, and/or the frequency of calls made. In this way the information and/or date of the call made can be used to determine whether the call fits the user profile.
Although information on the call such as the origination, the destination, the time, and date of the call can be determined as soon as the call is made from the call record and this information can be used immediately to determine whether the call represents fraudulent activity, if no fraudulent activity is detected, at the termination of the call the duration of the call can be determined and used to carry out a further check since in a preferred embodiment the user profile includes information on the duration of the calls. This specific embodiment provides a further check for fraudulent activity using the full duration parameter.
In accordance with another aspect of the present invention there is provided a method of controlling calls over a telecommunications network, the method comprising the steps of:
determining the origination of a call, and
determining whether the call is to be allowed or disallowed using a predetermined pattern of calls specific to the origination.
In accordance with a further aspect of the present invention there is provided apparatus for controlling calls over a telecommunications network, the apparatus comprising:
determining means for determining the origination of a call;
storage means for storing data for a pattern of calls specific to originations;
allowance determining means for determining whether the call is to be allowed or disallowed using the determined origination of the call and the stored pattern of calls specific to the origination; and
control means for controlling the call in accordance with the determination.
Thus in accordance with these aspects of the present invention if the call made does not fit the pattern for the origination of the call, the call is automatically disallowed or disconnected.
The call pattern can thus be used to control calls from the origination. It can allow for a level of usage of the telecommunications network which is not fixed but is determined as a pattern. This can also provide automatic protection against fraudulent calls since any calls which do not fit a user profile will not be allowed.
In order to allow a user to force the telecommunications network to allow a call, the user can be allowed to input a code which must be validated by the telecommunications network. If the code is valid the telecommunications network will allow the input of pattern update data to update the pattern of calls for user profile. In this way if a user wishes to significantly change their calling behaviour for example by making a series of long distance telephone calls, the user profile can be manually updated to accept this change in user behaviour.
The predetermined pattern of calls (user profile) is a pattern which is specific to the origination and can be formed during a xe2x80x98learningxe2x80x99 phase during which the calls made from an origination are recorded in order to form the predetermined pattern. Alternatively, the telecommunications network could form the predetermined pattern from the call records for the origination for a previous period of time. Further, the predetermined pattern could be formed based on the expected pattern of calls for the origination.